Leaking radiator - advise appreciated!

[Floopy21]

Hi, one of our radiators is dripping constantly & I have no idea what to do. The plumber can't get to us until next week - does anyone know if this is an easy problem to fix? Would a complete DIY novice (me!) be able to fix it?! TIA.

Where is it leaking from?

The bit at the bottom -not the one you turn to change the heat, the other one IYSWIM?! Can you tell I'm no good at this

On which side? One side there is a pipe that goes out and on the other usually a nut type thing you can tighten or loosen, iyswim.